Knowing how to properly string a tarp, tie off a canoe, or hang your food from bears, are all skills that depend on your ability to tie knots. A good practical knot is a thing of beauty; tying one requires logic, dexterity, and a whole lot of patience. Even if you’re not an outdoorsy person, learning how to tie knots (even basic knots) is great mental stimulation. And it’s fun too. Here’s a great online resource.